Exam 1 Pt. 2

Health effects of overweight and obesity

Coronary heart disease

Type 2 diabetes

cancers (endometrial, breast, colon)

Hypertension (HBP)

BMI

BMI: Weight (kg) / Height² (m²)

<18.5 = underweight

18.5-24.9 = normal/healthy

25-29.9 = overweight

>30 = obese

Doesn’t take into account body form and shape

Waist circumference

40 in for men

• usually apple, higher risk

35 in for women

• usually pear, lower risk

Not diagnostic of body fatness or health of individual

Taking into account muscle with weight

More muscle → more water → heavier

Body shape and overall health status should be considered on top of BMI

How fat cells behave (pathogenesis of adipocytes)

1. Endocrinopathy: hormonal abnormality (rare) → obesity = abnormal hormone levels (small percent)

2. Thermogenesis: obese people use energy more efficiently than healthy

3. Lipoprotein Lipase (LPL): higher rate of fat uptake from circulating plasma triglyc.

4. Viral infection: SMAM-1, avian adenovirus, AD-36, threefold body weight gain & more significant fat gain (rare)

Fully formed fat cells will not decrease in number/will only shrink

Fat cells and hormones (endocrine organs)

Leptin the satiety hormone: in hypothalamus - promotes energy balance, suppresses appetite, inc. energy expenditure

Adipose tissue releases this

Obese people have defect on this

Ghrelin

Secreted by stomach cells, inc. appetite

Promotes + energy balance (inverse correlation with body weight)

Psychological mindset influences ghrelin’s respons eto a meal

• mindset of indulgence inc. satiety

• promote sleep

Upcouples proteins

Environmental factors

Reflects interaction btw genes and the environment

overeating

• eating patterns

• food availability

• serving sizes → restaurant food

Therapy for obesity

1. Dietary management: impaired absoption - blocking intestinal absorption/non-digestible fat substitute

   1. compensating weight loss for protein

2. Exercise

3. Appetite suppressant (fenfluramine and phentermine)

   1. inhibit dietary lipid absorption (orlistat)

4. Surgical treatment (short bowel procedure, gastric surgery, lipectomy)

Better eating patterns

500/750 kcal/day

nutritional adequacy: rapid weight loss → loss of lean tissue → lower BMR → rapid weight regain when returning to normal cal intake

small portions

slow down

based on portion size → volumetric

Nutrient dense food

High levels of nutrients but with few calories

average cal/weight

Satiety

satisfied feeling of being full after eating

Protein: highest satiety value, support maintenance of lean body mass, generate food intake-related physiological responses

Carb: intermediate value. Higher glycemic index, less satiety

fat-gastric distention (fat paradox): least satiety value, most calories

Energy density

caloric value of a food/unit weight or volume

fiber lowers energy density

Eating in the morning

Produces greatest satiety and a lower total energy intake overall during the day

Environmental/behavioral modications

Atmosphere (lightig and decor)

Accessibility (ease and convenience)

Socializing (eating more w/ others)

Distractions (TV)

Having choices to eat

package/portion size

serving containers

Seeing your progress

Behavior and attitude

Positive, matter-of-fact attitude

Keeping track of behaviors

Small, time-specific goals

Rewards

Practice

Surgery for obesity

Gastric bypass: bypassing stomach and duodenum to jejunum

Intragastric balloon: controls feelings of fullness via band around top of stomach - tightened or loosened via adding/removing fluid

Gastric aspiration: contents of stomach 20-30 min emptied after each meal

Liposuction: removed fat deposit

No long term data

3 factors that use calories

BMR: amount of energy in cal that a person needs to keep body functioning at rest

• 60-75% of caloric requirement

• declines with ageing

Thermogenesis: keeping body temperature

• exercise

• non-exercise related

• diet-induced: eat something → gi system moves → creates heat → you get warmer

Factors affecting BMR

• Inc BMR

  • tall, thin people

  • children, adolescent, pregnant women

  • more lean tissue

  • fever

  • stresses

  • nicotine

  • caffeine

  • PMS

• Dec. BMR

  • cold

  • fasting

  • malnutition

  • sleep

Female calorie needs

19-20, 21-25: 2,000-2,400 cal

Male calorie needs

19-20, 21-25: 2,600-3,000 cal

Benefits of physical activity

Maintain weight

reduce HBP

reduce risk of type 2 diabetes, heart attack, stroke, cancer

Reduce arthritis pain, associated disability (rheumatoid arthritis)

Reduce risk for osteoporosis and falls

Reduce symptoms of depression and anxiety

Weight maintenance

Hard to know what leads to successful weight loss…however…: Exercise, careful eating patterns, self-monitoring

Maintained for at least a year

Social consequences/feelings

80-85% who lose weight likely to gain weight back

Fat alternatives: carb-based

cellulose, inulin, beta-glucan, pectin, resistant starch

• oatrim (hydrolyzed oat flour)

Fat alternatives: protein-based

microparticulated proteins

Fat alternatives: fat-based

salatrim: short and long chain acid triglyc. molecules (5kcal/g)

• short chain → less cal

• long chain is mostly stearic acid → harder to digest → no absorption

caprenin: poorly absorbed fatty acids (5kc/g)

olestra (synthetic): sucrose molecule w/ fatty acids, 0kcal/g

• cramps, gas, blatoing, diarrhea

Pancreatic lipase inhibitor

Blocks lipase from breaking down fat → no absorption and goes to waste

How to increase energy expenditure → lower fat

stimulating theromogenesis:

• methylxanthines: CNS stimulants, adenosine receptor antagonists, bronchodilators (caffeine, theophylline, theobromine)

• pungent ingredients (ginger, chiles, mustard)

• tea (catechin teoline)

pinolenic acid: polyunsat fat that suppresses appetite and regulates satiety hormones

conjugated linoleic acid

• reduce fat mass + inc. energy expenditure

• weight maintenance

ephedra sinica (Ma Huang)

• ephedrine & pseudoephedrine (not recc)

  • decreases BMI, tightens congestion, increases BP

thyroid supplement (not recc)

Circulatory system

Delivers oxygen, nutrients, and other substances to all body’s cells and to remove waste products of cellular metabolism

• pulmonary circulation

• systemic circulation

• Order in decreasing BP: arteries → capillaries → veins

  • veins have valves that make blood flow in one direction

  • muscle contractions control blood flow

Pulmonary circulation

Pathway that moves deoxygenated blood from right side of the heart to the lungs, and returns oxygenated blood to the left side of heart (blue to red)

• mostly deoxygenated blood

• removes CO2, picks up O2

Systemic circulation

Carries oxygen-rich blood from the heart to the rest of the body + returns oxygen-depleted blood back to the heart

• delivers O2 and nutrients, collects waste

Heart

70 bpm

Right atrium (receiving) + right ventricle (pumps out)

left atrium (receiving) + left ventricle (pumps out)

coronary circulation: heart pumps for itself

valves: control blood flow

Right side only connected to lung, left side is connected to everything else (high bp, thicker muscle)

Cardiac cycle

the complete sequence of contraction and relaxation that the heart goes through during one single heartbeat

• diastolic pressure: low, relaxing, blood flows in

• systolic pressure: high, muscle contracts, blood flows out

Cardiac action potentials

Sinoatrial node (SA node): electrical impulses to pump independent from the brain

Hematologic system

• Delivery of substances needed for cellular metabolism in the tissues

• defense against invading microorganisms and injury

• acid-base balance

Consists of cells and proteins 45-50% formed elements and the rest is plasma/serum

Cellular components

• erythrocytes

• leukocytes

• thrombocytes

erythrocytes

red blood cells: hemoglobin (iron), transports oxygen and CO2

non-nucleated disk

120 day life span

most abundant cells of blood!

leukocytes

white blood cells: immune cells with neutrophils that fight infection

mixture of many cell types → inflammatory and immune response

neutraphils have life span of 4 days

• granulocytes

• agranulocytes

thrombocytes

blood fragments drive homeostasis and blood clotting

fragmentation of very large cells, megakaryocytes

10 day life span

platelets

exposing positive charge to protein

platelet gets activated → coagulating properties get activated

other cells block, platelets themselves don’t coagulate

9-10 rxns to create complex

• vit K

• calcium

• fish oil

Lymphatic system

Lymphatic vessels and lymphoid tissues

Body’s drainage and immune surveillance network

• starts from tissue

• vein before heart that joins with circulatory system

functions:

1. recovery of extra fluid (3L doesn’t get repurposed)

2. filtration of fluid (before gets into circulatory system)

Primary lymphoid organs

• thymus (T-lymphocytes): Receives immature T-cell precursors from the bone marrow.

• bone marrow (B-lymphocytes): Acts as the maturation site for B lymphocytes (B cells).

Secondary lymphoid organs

• spleen: blood filtration, immune response, blood reservoir

• lymph nodes: tiny filters in immune system that trap germs, clear out waste from fluid, help body fight infection

• tonsils: frontline defense to trap and fight off germs

Defenses against infection

First line of defense: mechanical barriers, chemical barriers

• microflora

Second line of defense: inflammation response, phagocytosis (cell uses plasma to engulf virus)

• soluble factors

Third line of defense: specific immune responses, natural killer cells

Inflammation

Non-specific responses: biochemical and cellular process that occurs in vascularized tissues

Redness, swelling, heat, pain, loss of function (non-specfic)

• destroys injurious agents and remove them from inflammatory site

• confine injurious agent

• stimulate and enhance immune responses

• promote healing

Inflammation swelling

Blood vessels dilate, inc. blood flow to the area

Vascular permeability increased, resulting in outward leakage of plasma

Adhere to inner walls of vessels, migrate through vessel walls to site of injury

How white blood cells work when theres a cut

Neutrophils → eat infection, some die → pus

Manifestations of inflammation

local & non-specific: defense phase of healing

chronic inflammation: lasts longer than 2 weeks

Fever, leukocytosis (high white blood cells), inc. plasma protein

resolution & repair (begin during inflammation)

• resolution: restoration of original structure and physiologic function

• repair: replacement of destroyed tissue with scar tissue (collagen)

Innate vs. acquired immunity

Innate immunity: present at birth, lack immunologic memory

Acquired immunity: gained after birth as a result of immune response

1. active acquired immunity: produced by host after natural exposure to antigen/immunization (vaccines)

2. passive acquired immunity: preformed antibodies or T-cells are transferred to the recipient (taking antibodies from a person that was bit by snake and using it as cure, ready-made)

Characteristics of immune response

Specific and systemic effects

Two types of immunocytes or immunocompetend cells

• B lymphocytes (B cells): humoral immunity (white blood cells)

• T lymphocytes (T cells): cell-mediated immunity (destroys virus infected cells)

  • neutrophil but specific target

Antigen vs Immunogen

Used interchangeably

immunogen: something causing immune response, an antigen

antigen: something that binds to antibody

Building tolerance

Body recognizes what’s happening, recognizes as its own

B lymphocytes

Bone marrow

precursor cells that create antibody → not all active

• screen cells to see which one is best for antibody

• takes time!!!!!!!!!! (10-14 days)

Immunoglobin

Glycorotein (carb and mainly protein)

FAC, FC: antigen binding site

Y shape: two binding sites

Immunoglobulins

Ig…G,A,M,D,E

IgG: majority of antibodies

IgA: two antibodies attached in center

• first line of defense i nsaliva and body fluid

• production of this is last line of defense

IgM: largest (10 binding sites, 5 combined) → first antibody produced

IgE: allergic rxns

Functions of antibodies

Protecting host

binds to antigen directly, inactivates antigens (no adverse effect)

Opsonization: Antibody surrounds → many sites → T cell engulfs and kills it (phagocytosis)

• improve efficacy later

Secretory immune system

IgA: part of the saliva and body fluid (first line of defense)

Primary and secondary immune response

Primary response: IgM → IgG (10-14 days to complete)

• select + multiply

Secondary response (exposed to the same antigen): IgM production same, but igG is a lot faster with larger quantities

• why you wont get sick as much

• for vaccinations

live vaccine: less severe antigens that are alive (spray on nose, less severe side effects)

Cell-mediated immune response

T cell: mixture of diff cell types

• heterogenous

CD+ (CD8, CD4)

natural killer cells

Tolerance: our own cells may present as antigen

• autoimmune disease

Cellular products - signaling

Cytokines: a chemical signal produced by neutrophil, macrophage, Tcell, Bcell

• T cell activated → sends chemical signal to machophage to trigger immune response

• different names: monokines, lymphokines, interleukin

interferon: cytokine used for viral infections in body

• cell is protected from body

Adaptive immune response

How body’s immune system regonizes, fights, and remembers an antigen

Antigen presenting cells: an immune cell that detects, engulfs, and displays fragments of foreign invaders (antigens) on its surface to activate other cells of the immune system, particularly T cells

neutrophil fails → sends cytokines to macrophage (first cell type in immune response) → macrophage performs phagocytosis and swallows antigen → breaks down germ into smaller pieces (used as marker) → Helper T cell receives info and activates so it can target it better

Helper T cell multiplies, splits into two specialized branches

1. Th2 & B cells

   1. Th2 cells signals to activate mature B cells

   2. B cells multiply and transforms…

      1. into Plasma cells: produce antibodies (inflammation and binds to germs)

      2. memory B cells: fights off same germs faster next time

2. Th1 & Tc cells

   1. Th1 cells release chemical signals (IL-2) to activate cytotoxic t cells (Tccells)

   2. Tc cells scan body using CD8 markers to find infected cells

   3. Tc cells nject toxins to infected cells → destroys

   4. memory Tc cells for long-term

Infection

Inflammatory response - neutrophil - not great, non-specific and dies quickly

antigen presenting cell → helper T cell → cytotoxic tcell or B cell to produce antibody

suppressor T cell: once everything is cleared, this is a signal to stop the process

B and T cell becomes cells with memory